What might someone find useful?
A person might value being able to send digital money without a bank handling the transfer. Another might care about checking the public rules for themselves. Different people can value the same feature differently.
Bitcoin's current rules cap supply at 21 million BTC. A limit says how much can exist under those rules. It does not say how many people will want it or what they will offer for it.
Can a limited thing still lose value?
Imagine a printed ticket for an event. The number of tickets may be limited, but that alone does not tell you whether anyone wants to attend. The example is about scarcity and demand; Bitcoin is not an event ticket.
With bitcoin, interest and willingness to exchange can change even while the supply rules remain the same. A quoted price is what people are willing to exchange at that point, not a promise about the next exchange.
What does this mean for you?
You can understand why something has a price without deciding to own it. Usefulness, acceptance and changing demand are questions to separate. This page does not forecast a price or recommend a purchase.
Sources
- Bitcoin questions and answers
- Bitcoin Ecosystem project: source of the chain descriptions in the family note.